Motor fuel



Patented July 20, 1948 Pharis Miller, Mountainside, N. l auignor to Standard Oil Development Company, a corporation of Delaware No 1mm. Application sum a1, 1940, Serial No. seem 11 Claims. (Cl. 4H9) The present invention relates to an aviation fuel and more particularly relates to a fuel composition which gives improved performance in the aviation motor.

The problem of producing a proper fuel for use in the aviation motor is one that has attracted a large number of workers, due to the complexity of the requirements for a perfect fuel which will perform equally well under the different conditions encountered in the engine. For example,

the fuel requirements of the aviation engine are quite different under cruising conditions" from the conditions obtaining when the engine is accelerating during take-off or while the airplane is climbing.

As a solution to the problem of providing a proper aviation fuel suitable for use under the different conditions of operations, ithas been proposed that aromatics, naphthenes, isoparafsigned to prevent vapor lock and excessive evap'oration of the fuel. 7

The methylenecyclobutane may be employed in a fuel composition, the other constituents of which are predominantly isoparaifinic in nature.

' Thus. besides methylenecyclobutane, the fuel may comprise isopentane, isohexane, isoheptane, isooctane and the like. The improved fuel of my invention may also include amounts of tetraethyl lead, iron carbonyl and other anti-detonants such as the class of compounds illustrated by the amino toluenes.

In some instances it may be desirable to pre pare a fuel in accordance with the present invention which comprises methylenecyclobutane and quantities of the aromatics and/or naphthenes.

fins, cracked gasoline components and the like either comprise the major portion of the fuel or be added thereto in substantial amounts. Addition of tetra-ethyl lead and other anti-detonants such as amino toluenes and their homologs has also been proposed. All of these expedients,

while improving the various aviation fuel base stocks, provide an improvement in the fuels performance during either cruising conditions or during take-off or while the plane is climbing but not satisfying thefuel requirements suitable for both types of operation of the motor.

In accordance with the present invention, an improved aviation fuel is produced by the employment of suitable quantities of the hydrocar- I bon methylenecyclobutane which has the structural configuration It is contemplated that the amount of methylenecyclobutane comprising the aviation fuel will 100 F. This limitation of vapor pressure is de- It may be pointed out that 6 Mixtures of the latter types of hydrocarbons with isoparafllns form suitable base stocks to which the methylenecyclobutane may be added.

u The isoparafllns may be obtained from naturally occurring sources or may be produced synthetically as :by the well known alkylation and/or isomeri'zation reactions. Irrespective of the source of the isoparaflins, it is preferred to employ them in my fuel composition in relatively pure form. v

Suitable fractions of crude petroleum from crude oils of the Coastal type, which boil in the gasoline boiling range, may also form the base stock of my improved fuel. Generally, the hydrocarbon fractions will not have a boiling point which exceeds 350 F. 'When using crude petro leum fractions with methylenecyclobutane, it may be desirable to employ other blending agents such as alkylates and tetraethyl lead to obtain maximum utilization of the qualities of the admixture. The tetraethyl lead may be employed in most instances, in amounts not exceeding 6 cc, per gallon of fuel.

The compound methylenecyclobutane has been described in the literature (see for example Berichte der deutschen chemischen Gesellschaft v. 72:2021-2026 (1939) and Journal American Chemical Society v. 64:1142-7 (1942)).

It is suitably prepared from pentaerythrityl bromide as follows: g2 of pentaerythrityl bromide and 250 g. of zinc powder were placed in areaction flash and 250 cc. of 50% ethyl alcohol was slowly added. A hot water bath was placed around the flask until a localized reaction started. The product distilling over at 38 to 41 C. (l00.4-105.8 F.) was washed and dried over calcium chloride and-identified as methylenecyclobutane. It was tested by the A. S. T. M.

motor method and found to have a blending octane number of 99.

As a example ofthe, improved fuel composition, an aviation fuel in accordance with the present invention may be prepared by addin: 20 parts of methylenecyclobutane to 80 parts of an alkylatehaving a vapor pressure of four major amount of isoparaflinic hydrocarbons boilpounds Reid. The vapor pressure of this composition is slightly over 6 pounds Reid and is satisfactory for use in an aviation motor.

In another example, a fuel, in accordance with the present invention, is prepared by blending 25 parts of methylene-cyolobutane with a mixture composed of equal parts of 2. 2,-dimethyl-butane, commonly called neohexane and iso-octane. This composition is also satisfactory for use as an aviation fuel.

The nature and objects of the present invention having been described and illustrated, what is claimed as new and useful and desired to be secured by Letters Patent is:

1. An aviation fuel consisting essentially of a minor portion of methylenecyclobutane and a major portion of hydrocarbons boiling in the gasoline boiling range.

2. An aviation fuel in accordance with claim 1 in which the hydrocarbons boiling in the gasoline boiling range are obtained from crude petroleum.

3. An aviation fuel in accordance with claim 1 in which the hydrocarbons boiling in the gasoline range are produced synthetically.

4. An aviation fuel in accordance with claim 1 in which the methvlenecyclobutane comprises less than 50% by volume of the fuel.

5.'An aviation fuel consisting essentially of a minor amount of methylenecyclobutane and a hydrocarbons ing in the asoline boiling range.

a. An aviation fuel in accordance with 'claim 5 inwhich the. minor amount of methylenecyclobutlane comprises less than 50% by volume of the fue '7. An aviation fuel in accordance with claim 1 which comprises tetraethyi lead.

8. An aviation fuel in accordance with claim 5 which comprises tetraethyl lead.

9. An aviation fuel consisting essentially of methylenecyciobutane as a minor component and a mixture of isoparaflinic, naphthenic and aromatic hydrocarbons boiling in the gasoline boiling range as a major component.

10. An aviation fuel in accordance with claim 9 which comprises tetraethyl lead. v

11. An aviation fuel containing anti-detonants consisting essentially of a minor portion of metlhylenecyclobutane and a major portion of boiling in the gasoline boiling range.

PHARIS MILLER.

,BEFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS nautics, Technical Note 1023, February 1946, pages i-9. 

